- Kinetics of maltooligosaccharide hydrolysis in subcritical water
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The kinetics of the hydrolysis of maltooligosaccharides with a degree of polymerization (DP) of 3-6 in subcritical water was studied using a tubular reactor at temperatures between 200 and 260°C and at a constant pressure of 10 MPa. The maltooligosaccharide disappearance and product formation at residence times shorter than 50 s could be expressed by first-order kinetics. The rate constants for the hydrolysis of each maltooligosaccharide were evaluated. There was a tendency that the exo-site glucosidic bond was hydrolyzed faster than the endo-site one irrespective of the DP of the maltooligosaccharide. The hydrolysis of the maltooligosaccharides was consecutively preceded, and the time dependence of the hydrolysis for maltooligosaccharides with different DPs could be calculated by simultaneously solving the mass balance equations for all the possible saccharides.
- Khajavi, Shabnam Haghighat,Ota, Shuji,Kimura, Yukitaka,Adachi, Shuji
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- Anomer-Selective Glucosylation of l-Menthol by Yeast α-Glucosidase
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l-Menthol was glucosylated by the α-glucosidase (EC 3.2.1.20) of Saccharomyces cerevisiae using maltose as the glucosyl donor. When 50 mg of l-menthol and 1.6 M maltose in 10 mM citrate-phosphate buffer (pH 5.5) were incubated at 45°C, l-menthyl α-D-glucopyranoside (α-MenG) was α-anomer-selectively formed as a product. The specificity of the α-linkage was confirmed by 13C-NMR analysis. In the reaction mixture after 2 h, α-MenG was mainly accumulated in a crystalline form and the concentration of dissolved α-MenG was constant at 1.4 mM. The molar conversion yield of α-MenG produced based on the supplied l-menthol was maximally 30.7% at 48 h of reaction.
- Nakagawa, Hiroyuki,Yoshiyama, Masaaki,Shimura, Susumu,Kirimura, Kohtaro,Usami, Shoji
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- GLYCOSIDE COMPOUND
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Compounds of formula (I″) wherein: R11, R12, R13, R14 and R15 are hydrogen, hydroxyl, C1-6 alkyl, C1-6 alkoxy, C1-6 alkyl-carbonyloxy, or a G-O— group, and at least one of R11, R12, R13, R14 and R15 is a G-O— group, wherein G is a saccharide residue,X1 is a single bond, or a methylene group, an ethylene group, a trimethylene group, a vinylene group or —CH═CH—CH2—,X2 is —CO—O— or —O—CO—,p and q are integer ofs 0 to 7, and p+q=0 to 8,Y1 is methylene, ethylene or an alkenylene group having a carbon number of 2 to 15 and 1 to 3 double bonds, andR16 and R17 are hydrogen, methyl or ethyl, or R16 and R17 form a C3-6 cycloalkyl group, are useful as GLP-1 secretion promoting agents.
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Paragraph 0319; 0320; 0383; 0384
(2013/11/06)
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- Regioselective glucosylation of inositols catalyzed by Thermoanaerobacter sp. CGTase
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Monoglucosylated products of l-chiro-, d-chiro-, muco-, and allo-inositol were synthesized by regioselective α-d-glucosylation with cyclodextrin glucosyl transferase from Thermoanaerobacter sp. after hydrolysis of by products with Aspergillus niger glucoamylase. While the reactions carried out with d-chiro-, muco-, and allo-inositol resulted in the regioselective formation of monoglucosylated products, two products were obtained in the reaction with l-chiro-inositol. Through the structural characterization of the glucosylated inositols here we demonstrated that the selectivity observed in the glucosylation of several inositols by Thermoanaerobacter sp. CGTase, is analogous to the specificity observed for the glucosylation of β-d-glucopyranose and equivalent glucosides.
- Miranda-Molina, Alfonso,Marquina-Bahena, Silvia,Alvarez, Laura,Lopez-Munguia, Agustin,Castillo, Edmundo
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p. 93 - 101,9
(2020/08/20)
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- COMBINED USE OF DIPEPTIDYL PEPTIDASE IV INHIBITOR COMPOUND AND SWEETENER
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The present invention provides a novel therapeutic or preventive method, a pharmaceutical composition and use thereof, that exhibit superior anti-obesity effects (body weight-reducing (losing) effects and/or body fat mass-reducing effects). Specifically, the present invention provides a pharmaceutical composition comprising the combination of a dipeptidyl peptidase 4 inhibitor and a sweetener having a GLP-1 secretion-stimulating action, as well as use thereof for the manufacture of a medicament. The present invention also provides a method for treating or preventing obesity, comprising administering an effective amount of (a) a dipeptidyl peptidase 4 inhibitor and (b) a sweetener having a GLP-1 secretion-stimulating action to a patient suffering from symptoms of obesity.
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- Branched alpha-glucan, alpha-glucosyltransferase which forms the glucan, their preparation and uses
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The present invention has objects to provide a glucan useful as water-soluble dietary fiber, its preparation and uses. The present invention solves the above objects by providing a branched α-glucan, which is constructed by glucose molecules and characterized by methylation analysis as follows: (1) Ratio of 2,3,6-trimethyl-1,4,5-triacetyl-glucitol to 2,3,4-trimethyl-1,5,6-triacetyl-glucitol is in the range of 1:0.6 to 1:4;(2) Total content of 2,3,6-trimethyl-1,4,5-triacetyl-glucitol and 2,3,4-trimethyl-1,5,6-triacetyl-glucitol is 60% or higher in the partially methylated glucitol acetates;(3) Content of 2,4,6-trimethyl-1,3,5-triacetyl-glucitol is 0.5% or higher but less than 10% in the partially methylated glucitol acetates; and(4) Content of 2,4-dimethyl-1,3,5,6-tetraacetyl-glucitol is 0.5% or higher in the partially methylated glucitol acetates; a novel α-glucosyltransferase which forms the branched α-glucan, processes for producing them, and their uses.
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Page/Page column 18-19
(2010/06/11)
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- Molecular cloning and functional expression of a new amylosucrase from Alteromonas macleodii
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The presence of amylosucrase in 12 Alteromonas and Pseudoalteromonas strains was examined. Two Alteromonas species (Alteromonas addita KCTC 12195 and Alteromonas macleodii KCTC 2957) possessed genes that had high sequence homology to known amylosucrases. Genomic clones containing the ASase analogs were obtained from A. addita and A. macleodii, and the deduced amino acid sequences of the corresponding genes (aaas and amas, respectively) revealed that they were highly similar to the ASases of Neisseria polysaccharea, Deinococcus radiodurans, and Deinococcus geothermalis. Functional expression of amas in Escherichia coli was successful, and typical ASase activity was detected in purified recombinant AMAS, whereas the purified recombinant AAAS was nonfunctional. Although maximum total activity of AMAS was observed at 45 °C, the ratio of transglycosylation to total activity increased as the temperature decreased from 55 to 25 °C. These results imply that transglycosylation occurs preferentially at lower temperatures while hydrolysis is predominant at higher temperatures.
- Ha, Suk-Jin,Seo, Dong-Ho,Jung, Jong-Hyun,Cha, Jaeho,Kim, Tae-Jip,Kim, Young-Wan,Park, Cheon-Seok
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experimental part
p. 1505 - 1512
(2010/03/01)
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- Isolation and characterization of a novel thermostable neopullulanase-like enzyme from a hot spring in Thailand
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A gene encoding a thermostable pullulan-hydrolyzing enzyme was isolated from environmental genomic DNA extracted from soil sediments of Bor Khleung hot spring in Thailand. Sequence comparison with related enzymes suggested that the isolated enzyme, designated Env Npu193A, was most likely a neopullulanase-like enzyme. Env Npu193A was expressed in Pichia pastoris as a monomeric recombinant protein. The purified Env Npu193A exhibited pH stability ranging from 3 to 9. More than 60% of enzyme activity was retained after incubation at 60°C for 1 h. Env Npu193A was found to hydrolyze various substrates, including pullulan, starch, and γ-cyclodextrin. The optimal working condition for Env Npu193A was at pH 7 at 75°C with Km and Vmax toward pullulan of 1.22 ± 0.3% and 23.24 ± 1.7 U/mg respectively. Env Npu193A exhibited distinct biochemical characteristics as compared with the previously isolated enzyme from the same source. Thus, a culture-independent approach with sequence-basing was found to be an effective way to discover novel enzymes displaying unique substrate specificity and high thermostability from natural bioresources.
- Tang, Kittapong,Kobayashi, Rutchadaporn Sriprang,Champreda, Verawat,Eurwilaichitr, Lily,Tanapongpipat, Sutipa
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p. 1448 - 1456
(2008/12/20)
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- ACCELERATOR FOR MINERAL ABSORPTION AND USE THEREOF
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The present invention has an object to provide an accelerator for mineral absorption and a composition containing the accelerator. The object is solved by providing an accelerator for mineral absorption comprising cyclic tetrasaccharide and/or saccharide derivatives thereof and a composition containing the accelerator.
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Page/Page column 14
(2008/06/13)
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- Expression, purification, and characterization of the maltooligosyltrehalose trehalohydrolase from the thermophilic archaeon Sulfolobus solfataricus ATCC 35092
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The maltooligosyltrehalose trehalohydrolase (MTHase) mainly cleaves the α-1,4-glucosidic linkage next to the α-1,1-linked terminal disaccharide of maltooligosyltrehalose to produce trehalose and the maltooligosaccharide with lower molecular mass. In this study, the treZ gene encoding MTHase was PCR-cloned from Sulfolobus solfataricus ATCC 35092 and then expressed in Escherichia coli. A high yield of the active wild-type MTHase, 13300 units/g of wet cells, was obtained in the absence of IPTG induction. Wild-type MTHase was purified sequentially using heat treatment, nucleic acid precipitation, and ion-exchange chromatography. The purified wild-type MTHase showed an apparent optimal pH of 5 and an optimal temperature at 85°C. The enzyme was stable at pH values ranging from 3.5 to 11, and the activity was fully retained after a 2-h incubation at 45-85°C. The kcat values of the enzyme for hydrolysis of maltooligosyltrehaloses with degree of polymerization (DP) 4-7 were 193, 1030, 1190, and 1230 s-1, respectively, whereas the kcat values for glucose formation during hydrolysis of DP 4-7 maltooligosaccharides were 5.49, 17.7, 18.2, and 6.01 s-1, respectively. The KM values of the enzyme for hydrolysis of DP 4-7 maltooligosyltrehaloses and those for maltooligosaccharides are similar at the same corresponding DPs. These results suggest that this MTHase could be used to produce trehalose at high temperatures.
- Fang, Tsuei-Yun,Tseng, Wen-Chi,Guo, Meng-Shin,Shih, Tong-Yuan,Hung, Xing-Guang
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p. 7105 - 7112
(2008/02/03)
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- Synthesis and characterisation of novel chromogenic substrates for human pancreatic α-amylase
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Derivatives of maltose and maltotriose were chemically synthesised as substrates for human pancreatic α-amylases and subjected to kinetic analysis. Rates measured were shown to reflect both hydrolysis and transglycosylation reactions. 4-O-Methylated derivatives of these substrates underwent only hydrolysis, thereby simplifying kinetic analyses. These modified substrates may be used for the detection and kinetic analysis of α-amylases, and are useful in rapidly screening for novel α-amylase inhibitors and for subsequent kinetic characterisation.
- Damager, Iben,Numao, Shin,Chen, Hongming,Brayer, Gary D.,Withers, Stephen G.
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p. 1727 - 1737
(2007/10/03)
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- Synthesis of trisaccharides and tetrasaccharides by means of intramolecular glycosylation supported by rigid spacers
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Treatment of α,α′-dibromo-m-xylylene with 6-O-unprotected thiomaltoside 4 as glycosyl donor (→ 5), followed by 4-O-unprotected galactoside derivative 6 as acceptor, afforded β-linked macrocyclic trisaccharide 9β in high yield after removal of the 3-O-MPM protective group and subsequent intramolecular glycoside bond formation. Similarly, by the same sequence of steps, the corresponding tetrasaccharide 14β was obtained from 5 and 4b-O-unprotected lactoside 11. For reiterative glycoside bond formation, treatment of α,α′-dibromo-m-xylylene with 3-O-unprotected thioglycoside 15 as donor (→ 16), followed by 4,6-O-unprotected glucoside, and subsequent glycosylation afforded macrocyclic maltotrioside 22, which was transformed into known maltotrioside 23. A sight modification of the protecting-group pattern in maltotrioside synthesis resulted in generally higher yields in the ligation of the building blocks to the m-xylylene spacer, particularly in the second glycosylation step, thus providing macrocyclic maltotrioside 40α, which was transformed into known maltotriosides 41α and 41β.
- Mueller,Schmidt, Richard R.
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p. 2055 - 2066
(2007/10/03)
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- Composition and method for stimulating pollen germination
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Composition for application, in particular to leaves, comprising an excipient, the conventional constituents of compositions for application, in particular to leaves, and an active ingredient, characterized by the fact that the active ingredient is constituted by at least one phytosanitary product capable of stimulating the germination of pollen grains, selected from the group comprising: oligosaccharides having a degree of polymerization up to 10 and comprising up to 10, preferably up to 5 and, even more preferably, two glucidic units linked by β1-3, β1-4 et α1-3, particularly those of the group comprising laminaribiose, cellobiose, nigerose, laminaritriose, laminaritetraose and laminaripentaose, derivatives of the above oligosaccharides substituted on the free anomeric carbon atom or on all the carbon atoms having a free hydroxide by a radical selected from the group comprising: C1to C5alkyl radicals, preferably the methyl radical, C1to C5acyl radicals, preferably the acetyl radical, aryl radicals, preferably pyridylamino radicals, cycloalkyl radicals from Cxto Cy, amines, the N-acetyl radical and sulfate and phosphate radicals.
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- Study of the action of human salivary alpha-amylase on 2-chloro-4-nitrophenyl α-maltotrioside in the presence of potassium thiocyanate
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The degradation mechanism of a synthetic substrate, 2-chloro-4-nitrophenyl α-maltotrioside (CNP-G3), by human salivary alpha-amylase (HSA) was investigated by kinetic and product analyses. It was observed that the enzyme attacked the various CNP-maltooligosaccharides (CNP-G3, to CNP-G6) releasing free CNP. Addition of 500 mM potassium thiocyanate (KSCN) was also found to greatly increase the rates of CNP-release. It was the fastest with CNP-G3, and, in the presence of KSCN, was almost comparable to that of degradation of maltopentaose (G5). On the other hand, addition of KSCN decreased the rate of cleavage between glucan-glucan bonds in maltopentaose. Product analysis showed that KSCN addition altered the cleavage distribution which occurred 100% at the bond between CNP and G3, and that product distribution of free CNP was largely dependent on substrate concentration. Formation of CNP-G6, a larger product than the original substrate CNP-G3, was found to be present in the digest at high concentrations of substrate and in the presence of KSCN. Based on these results, a degradation pathway for CNP-G3 involving transglycosylation besides direct hydrolysis is proposed. The increase of the CNP-release by the addition of KSCN would result from a corresponding increase in the interaction between the CNP moiety and the corresponding subsite near the catalytic site, as well as the enhancement of the catalytic efficiency.
- Suganuma, Toshihiko,Maeda, Yoshiaki,Kitahara, Kanefumi,Nagahama, Tomonori
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p. 219 - 227
(2007/10/03)
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- Dehydrative Glycosylation Using Heptabenzyl Derivatives of Glucobioses and Lactose
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Dehydrative glycosylations of the 2-, 3-, 4-, and 6-OH groups of D-glucopyranose with hepta-O-benzyl derivatives of glucobioses (O-D-glucopyranosyl-(1->n)-D-glucopyranose; n = 2, 3, 4, or 6) and lactose, in the presence of a ternary mixture of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, and triethylamine in dichloromethane showed that the selectivity of the reaction depended on the anomeric configuration and the linking position to the reducing tribenzylglucose moiety of the nonreducing tetrabenzylglucosyl residue and on the class of the OH group to be glycosylated.The use of a quaternary mixture of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, N,N-dimethylacetamide, and triethylamine made all but the β(1->2)-linked biosyl donor undergo α-condensation.Several new linear trisaccharides were obtained via debenzylation of the condensates.
- Koto, Shinkiti,Morishima, Naohiko,Shichi, Sonoko,Haigoh, Hisamitsu,Hirooka, Motoko,et al.
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p. 3257 - 3274
(2007/10/02)
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- Subsite Structure of Chalara paradoxa Glucoamylase and Interaction of the Glucoamylase with Cyclodextrins
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The action of Chalara paradoxa glucoamylase (raw-starch-digesting enzyme) was studied with linear and cyclic maltodextrins.Subsite affinities (Ai) of the amylase were evaluated by the subsite theory.The active site was considered to be made up of seven subsites: A1 = 0.05 kcal/mol, A2 = 4.99 kcal/mol, A3 = 1.30 kcal/mol, A4 = 0.77 kcal/mol, A5 = 0.33 kcal/mol, A6 = 0.21 kcal/mol and A7 = 0.21 kcal/mol.Inhibitions by alpha-, beta-, and gamma-cyclodextrins were competitive for starch digestion by C. paradoxa glucoamylase.The inhibitor constants (Ki) of α-, β-, and γ-cyclodextrin for the amylase were 8.9, 1.4, and 3.9 mM, respectively.The Michaelis constant (Km) of 6-O-α-maltosyl-α-cyclodextrin digestion was 0.79 mM for the amylase.
- Monma, Mitsuru,Yamamoto, Yoshihiro,Kainuma, Keiji
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p. 1503 - 1508
(2007/10/02)
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- ENZYMIC SYNTHESES OF DOUBLY BRANCHED CYCLOMALTOHEPTAOSES THROUGH THE REVERSE ACTION OF Pseudomonas ISOAMYLASE
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Two and three new cyclomaltoheptaose (β-cyclodextrin, cG7) derivatives, respectively, were identified among the products obtained by the action of Pseudomonas isoamylase on maltose and maltotriose, and cG7.They were 6A,6D-di-O-α-maltosyl-cG7 and 6-O-α-(62-O-α-maltosyl)maltosyl-cG7, and 6A,6D-di-O-α-maltotriosyl-cG7, 6-O-α-(63-O-α-maltotriosyl)maltotriosyl-cG7, and 6-O-α-(62-O-α-maltotriosyl)maltotriosyl-cG7.In addition, 61- and 62-O-α-maltosylmaltose were identified as mutual condensation products of maltose.Maltose was the smallest substrate to act as both an acceptor and a donor for the action of Pseudomonas isoamylase.
- Abe, Jun-ichi,Hizukuri, Susumu,Koizumi, Kyoko,Kubota, Yoko,Utamura, Toshiko
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- ELECTROCHEMICAL DETECTION OF REDUCING CARBOHYDRATES PRODUCED BY THE TRANSFERASE ACTION OF YEAST DEBRANCHING ENZYME ON MALTOSACCHARIDES
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A sensitive method for the detection of maltosaccharides up to maltoheptaose is based on an electrochemical detector using bis(1,10-phenanthroline)-copper(II) in the post column reaction after h.p.l.c. on an amino-bonded column.This method has been used for the analysis of the maltosyl and maltotriosyl transferase action of the yeast debranching enzyme with maltosaccharides as the substrates.The smallest donor substrate for maltosyl transfer was maltotetraose, and maltopentaose, maltohexaose, and maltoheptaose were donor substrates for both maltosyl and maltotriosyl transfers.Maltosyl residues were transferred in preference to maltotriosyl residues from maltopentaose, but maltotriosyl residues were transferred prefentially from maltohexaose and maltoheptaose.Maltotriose is an acceptor but not a donor of maltosyl and maltotriosyl transfers.
- Tabata, Shiro,Ide, Takeshi
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p. 245 - 252
(2007/10/02)
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- Pullulanase-Amylase Complex Enzyme from Bacillus subtilis
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A novel pullulanase-amylase complex enzyme, which hydrolyzes pullulan into maltotriose as well as starch into maltose and maltotriose as the main products, was found in the culture filtrate of a strain of Bacillus subtilis newly isolated from soil.The enzyme was purified to almost complete homogeneity by means of calcium phosphate gel adsorption, DEAE-Sepharose column chromatography and Bio-gel A-1.5 m filtration.The optimum pH of the pullulanase activity was observed at around 7.0 to 7.5, with a discernible shoulder around pH 5.0.While the optimum pH of the amylase activity was 6 - 7.The optimum temperatures of the pullulanase and amylase activities were about 60 deg C and about 50 deg C, respectively.The molecular weight was estimated to be about 450,000 by the gel filtration method.The enzyme could be used for the production of glucose from starch with glucoamylase and the production of a new type of syrup containing a relatively high amount of maltotriose, 50 - 55 percent, from starch.
- Takasaki, Yoshiyuki
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- Synthesis of branched cyclomalto-oligosaccharides using Pseudomonas isoamylase.
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Branched cyclomalto-oligosaccharides (cyclodextrins) were synthesised from cyclomalto-oligosaccharides and maltose or maltotriose through the reverse action of Pseudomonas isoamylase. The reaction rate was greater with maltotriose than with maltose, and with increasing size of the cyclomalto-oligosaccharide (cG6 less than cG7 less than cG8). Maltotriose is effective as both a side-chain donor and acceptor, and three isomers of 6-O-alpha-maltotriosylmaltotriose (branched G6) were formed through mutual condensation, but maltose was effective only as a side-chain donor. Each branched cyclomalto-oligosaccharide and G6 was purified by liquid chromatography, and their structures were determined by chemical, enzymic, and 13C-n.m.r. spectroscopic analyses.
- Abe,Mizowaki,Hizukuri,Koizumi,Utamura
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